The use of misting devices to produce a cooling effect in a relatively high temperature environment is well known. The cooling effect is produced by an evaporation and absorption of an atomized or vaporized liquid (usually water) by a surrounding high temperature gas (usually air). This evaporation and absorption process reduces the air temperature in an area proximate to the mist. Atomizing or misting nozzles connected to a pressurized water supply are commonly used to produce this cooling mist or vapor.
A known application of this principal attaches multiple misting nozzles to a length of hollow pipe. The pipe is closed at one end and is attached to a pressurized water supply at another end. The pipe is attached to a fixed surface or support such as a post or several ceiling joists. This provides a cooling mist for a local area covered by the fixed misting system. Other applications use a portable or personal misting device that can be easily carried by an individual wherever they go and activated whenever the individual chooses. One such device incorporates an air pumping mechanism with a portable water bottle and a valve actuated misting nozzle. The air pumping mechanism uses a single cup seal attached to an end of a hollow plunger rod residing inside a hollow cylinder, to force air inside the hollow cylinder into the water bottle. For this device the hollow cylinder is located inside the water bottle and has passages, seals and one-way valves that allow uni-directional flow from the cylinder into the water bottle. By sliding the plunger rod back and forth inside the hollow cylinder, air is taken in through a one-way valve in the hollow plunger rod, and passed into the hollow cylinder where the cup seal forces the air through another one-way valve and into the water bottle. The valve actuated misting nozzle is attached to the top of the water bottle such that when the water bottle has a sufficient amount of water and compressed air, pressing or holding the valve down causes water to be dispersed through the misting nozzle.
Unfortunately this portable misting device requires excessive repetitive pumping action to provide sufficient air pressure inside the water bottle before misting can take place. The number of pumps determines the amount of air pressure inside the water bottle which determines the duration and pressure of the mist available to the individual. Longer lasting, higher pressure mist is desirable for cooling purposes. Unfortunately to achieve a desirably longer lasting higher pressure mist, the individual needs to perform more and more pump strokes to increase the air pressure in the water bottle. Furthermore, the valve actuating the misting nozzle must be held depressed during the misting operation, resulting in an inconvenient hands-on type of operation. This misting device uses compressed air to force water through the misting nozzle which requires seals and valves that can provide not only water-tight but air-tight connections as well.
Accordingly a need exists for a portable automatic misting device that can pressurize and automatically disperse a liquid through a misting nozzle for a desirable length of time. Such a device should also provide for ease of portability and operation.